Improvement in carriage spring



B. T. HENRY.

AM. PHUTD-LITPHLCD. N Y (DSBURNE'S PROCESS) @geiten tats uztrnt @fficeB. '.ll.v HENRY, `OF NEW HAVEN, CONNECTICUT. Letters Patent No. 64,866,dated May 21,1867.

IMPROVEMENT IN CARRIAGE SPRING.

l TO ALL WHOM IT MAY CONCERN: y i

Be it known' that I, B. T. HENRY, of New Haven, in thecounty of NewHaven, and State'of Connecticut, have invented a new Improvement inElliptic Springs for Carriages; and I do hereby declare the following,when taken inconnection with the accompanying drawings and the lettersof reference marked thereon, to be a full, clear, and exact descriptionof the same, and which said drawings constitute pa/rt of thisspecification, and represent, 1n-

Figure 1, a side view.

Figure 2, a top view.

Figure 3, a. longitudinal central section; and in Figure 4, a transversecentral section. y

By the expression of elliptic spring I wish to he understood ascomprehending a half as well as whole elliptic.

This invention is designed to avoid the great friction and wear vwhichexist in the common elliptic springs, such as are formed fromseveralleaves overlyingA each other, as also to produce a spring ofgreater elasticity -at less cost; and my invention consists in formingthe plate of the spring of nearly an equal thickness, and

raising upon the surface one or more ribs, diminishing in height towardthe ends; and in order to the clear understanding of my invention, aswell as to enable others to construct 'the same, l will proceed to a.description thereof as illustrated in the accompanying drawings.

I prefer' te' roll the spring in a common rolling-mill, one roll ofwhich shall be of acireumference equal at least to the length of thespring to be rolled; and in the said roll there is formed a concavegroove, beginning at nothing, and gradually growing deeper to thecentre, and then gradually diminishing'to nothing at the place ofbeginning. Through rolls thus constructed the steel is passed, whichforms a flat plate, a, and the groove inA the one roll forming a rib, d,in the centre, as seen in iig. 4, the said rib diminishing in heightfrom the centre toward either end, as seen in figs. 1 and 3, while theplate may be of nearly an equal thickness, and the rib suillcient togive the required strength to the single plate. If preferred, more thanone rib may be employed; and, if preferred, a flat leaf may be placedbeneath the spring thus formed; or, a leaf, having upon its undersurface a cavity corresponding to the rib, may be placed upon the topfor the purpose of -strengthening the spring'; yet it is better to makethe rib and plate suiicently strong, so as not to require the use ofother leaves. Other, and perhaps better, means than that described inthe production ofthis spring may be employed; yet this plan is the bestknown to me.

I have described the rib as having a convex surface, as seen in fig. 4,and this I prefer, as it gives to the spring a neater and more finishedappearance than would be were the rib of diferent form; yet the form oftherib is no part of the invention.

Having thus fully described my invention, what I claim as new anduseful, and desire to secure by Letters Patent, isv l An ellipticspring, having one or more ribs d formed upon its surface, substantiallyas and for the purpose set forth.

B. T. HENRY.-

Witnesses:

A. J. TIBBiTs, J. H. SHUMWAY.

